I don’t understand Anything u just wrote
Answer:
80
Step-by-step explanation:
Initial ratio:
Teachers to students
1 : 15
Ratio after:
Teachers to students
3 : 40
The number of students did not change, so we can make the students of the initial ratio and the students of the ratio after the same.
1 : 15 = 8 : 120
3 : 40 = 9 : 120
120 units = 1200
1 unit = 
Initial teachers = 8 units = 
2x + 3y = 13
–6x + 4y = 0
multiply the first equation by 3
6x +9y = 39
then add the 2nd equation to the first
6x +9y = 39
–6x + 4y = 0
-------------------
13y = 39
divide by 13
y =3
now take an equation and solve for x by substituting in y
2x +3y =13
2x +3(3) =13
2x+9 =13
subtract 9 from each side
2x =4
divide by 2
x=2
Answer (2,3)
Choice A
The y-intercept of the graph equation is (0,-4)
(4x - y)/(2y + x) when x = 3 and y = 3 is
(4(3) - 3)/(2(3) + 3) = (12 - 3)/(6 + 3) = 9/9 = 1